This is a second resubmission of a competing renewal application, following three years of initial support. The applicant has determined that hippocampal LTP is ethanol sensitive. NMDA receptors seem to play a clear role in this sensitivity. However, inhibition of LTP by 100 mM ethanol exceeds that produced by inhibition of NMDA receptors by other pharmacological agents, leading to the hypothesis that an additional component of the inhibition may result from a ethanol's effects on GABAA receptors. This proposal further explores the actions of ethanol on NMDA receptor function, as well as probing the contribution and nature of GABAA receptors.